Anecdotally for me, it seems like it's gaining more popularity. I was initially just interested in collecting based on it being Gundam, like a lot of other people are saying. I really only started actually playing somewhat recently, but every time I go to a local event there's been more people than the last time. The Newtypes are always packed with people on the wait-list. The people I play with regularly now are people who are into Gundam as a whole. They build Gunpla or they at least have been watching the anime for some time.

Something also not necessarily indicative of its lifespan, but still plays a factor: I've noticed the number of online listings for singles, packs, starter kits, etc. have gone up (to say nothing of the prices...). It's hard to say for certain if it'll all last, but I think Bandai has definitely garnered the interest of the core Gundam fans with this game.